Variable-speed gear



Sept. 9, 1930. H., HERRMANN 1,775,460

VARIABLE SPEED GEAR Filed March 25. 1929 Fig. i

Patented Sept. 9, 1930 UNITED f STATES PATENT oEFlcE i HEINEIcn HEEEMANN, or ESSEN, GEEMANr, Ass1NoEI To EEIED. xaurr AKTIEN, cEsELLscHAE'r, or EssEN-oN-THE-BUHE, GERMANY VARIABLE-SPEED GEAR Application led March 1929, Serial No. 350,(J85, and in Germany April 5, 1928.

The invention relates to variable speed gear and particularly to gears permitting passage from one speed to another, without interruption o f'the transmissionvof power, of

the type described in Letters Patent No. 1,724,202, of August 13, 1929. The invention has yfor its object a variable speed gear which allows the provision 'of as many 'gearwheel .trains as desired for different speed steps in a .very simple and clear manner, the driving wheels of these gear wheel trains being arranged co-axially with a.slip.clutch. This object is obtained according to the'invexition f by connecting each of these driving wheels independently of the others with one half of the slip-clutch, by means of a, coupling adapt- I ed to be operated at will, and further, by connecting on the one hand, by means of another couplin to be operated at will, the otherhalf vzo of the .s ip-clutch with the adjacent driving wheel of said 'gear wheel trains, and on the other hand, each following driving wheel with the preceding one.

In order that the invention. can be more easily understood, two embodiments of the same are illustrated in the accompanying drawing, each embodiment representing a variable speed gear intended to be used with a Diesel locomotive. .In'the drawing Fig.l 1 is a longitudinal section through the first embodiment, and

Fig. 2 is a similar section through the other embodiment. l

The embodiment illustrated inr Fig. 1 will be described first. 1

A. denotes `the ydriving shaft of the gear whichl shaft is connected e. g, with a Diesel engine, while B denotes the shaft 'serving' to manner a pump casing 'A1.rigid on shaft A and includingtwo oppositepump cylinders d each lodging a piston-D, and acrank c1 arranged-on shaft C with which crank are.

` connected the pistons-D b means of rods d1, e. g. in the manner of a s ot -and cra'nk gear.

- casing' amd is connected to the hub a* by 'while the following gear wheel trains Y 'J P, and K Q each p roduce a speed highertransmit the motion to thewheelsof the loco;

coupling.V This latter comprises -in known Thecylinders a2 are in communicationover a or opened entirely. When valve E in pipe a3 is completely closed, a rigid connection exists between the two halves, formed by the pump casing A1. and the crank c1, of the liquid coup-- u ling; when valve E is completely open, no

power transmission takes place from shaft Ato shaft C; when valve E is partly closed, i

power transmissionftakes place with a relative motion of the coupling halves A1 and e1.- The coupling thus forms a slip-clutch like the main coupling described in the patent cited above. .The pump casing A1 is mounted on shaft C opposite shaft A by means of a long hub a* adjacent to which is arranged a sleeve F which may rotate on shaft C like the pump al spring coupling f1. A Y

The variable speed gear comprises four gear wheel trains each corresponding to one speed step. The driving wheels, denoted by G, H, J, K, of these gear trains are mounted for free rotation side by side on shaft C. The

-driven Wheels in mesh with wheels G, H, J, K

mounted side by sideon shaft B. The gear wheel train'G, M` next to the main couplin A1 c1 is intended to produce the lowest s eeN, I

than the precedingfone. In the embodiment 1 shown the driven wheel Q of the train -K Q of the highest. speed step is rigidly mounted on, shaft B, while the driven wheels P, N, M of the trains of the preceding speed steps are each. connected to, shaft. B by ,free wheel couplings p1 nl m1.. .The spur wheel Vho.w. neve might -connected to shaft B llkewise by a free'wheel coupling.

.The intermediate shaft C has rigidly: mounted on it' between sleeve FA and-spul',4 wheel G fcoupling' half c2 fitted with claws.

-This half .cooperates with la. corresponding' couplin half g1 'provided on the 'hub of spur' wheel on sleeve ,located on its left-hand side. Furthermore an'oter coupling sleeve R is nsf located on its right=hand side, and' "witha cou ling half f2 of analogous' design tion at all is established with sleeve Il in its right-hand end position. llellce, spul' wheel G can be connected, by a coupling adapted to operate at will and formed by the parts g1, R, c2, on the one hand with the driven half c1 of the slip-clutch A1 c1 and on the other hand, by the coupling g1, R, f2 over sleeve F and spring coupling f1 with the driving half A1 of the slip-clutch. Coupling arrangements that correspond exactly to tllat formed by the parts c2, g1, f2, R are provided between the spur wheels G H. H J, and JK, the coupling half c2 corl'esponding to coupling half 03,' c, c, likewise rigidly mounted on` shaft C, wllile coupling half g1 corresponds to coupling halves h1, i1, r, coupling half f2 to halves g2, L'', i2, and sleeve R to sleeves R1, R2, R3.

In describing the mode of operation I start from the position illustrated in Figure 1. The main coupling A1 c1 is out of gear, so that the pump casing A1 can revolve relatively to shaft C witllout power transmission. The couplingr sleeve R is in a position interconnecting the coupling halves g1 and c2. The sleeves R1, R2, R3 are in the right-hand end position in -which the respective couplings are out of gear. To start, the main coupling is thrown into gear by setting valve E, whereby lirst a slip motion of the coupling halves A1, 01 takes place and then, after complete closure of valve E, a rigid connection is effected between shafts A and C. Shaft B is now driven through the members A, A1 c1, C c2, R, g1 G, M, m1. Now sleeve R is shifted to the left-hand end position whereby spur wheel G is coupled with sleeve F. This can be effected without endangering the parts of4 the gear, since sleeve F is connected with the half A1 of the main coupling by spring coupling f1 and thus rotates at the same angular speed as sleeve R which during the described operation is likewise in connection with the half A1 through c2 C c1. After the sleeve R has been shifted, the main coupling is thrown out again. An interruption of the power transmission, however, cannot take place, hecause spur wheel G has been connected to the driving half A1 of the main coupling previous to the throwing out of the lnain coupling, through g1, R, f2, F f1, at, independently of the coupling action of main coupling A1 c1. The power transmission to shaft B now takes place through A A1 a1, f1 F f2, -R, g1 G, M m1. p The intermediate shaft C with the crank, c1 now takes part in the rotation .only by the friction existing in the mechanism of the main coupling, this rotation taking place with the same angular speed of coupling half A1.

For the purpose of setting the gear to the next higher speed step, to be obtained by means of the gear wheel train H, N, spur I wheel H is coupled with the coupling half c and tllerewitll also with shaft C, by shifting the coupling sleeve R1. Dangerous blows cannot occur in this operation, as shaft C is only driven by friction. After this coupling operation shaft C can revolve only at an angular speed which is lower than that of coupling half A1, as the anglllar speed of spur wheel N at most can be equal to that of shaft B driven by half A1 through the train G, M41 and the angular speed of shaft C tllerefore lllust be lower with regard to the lower gear ratio of the wheel train H, N. The difference between the speeds of shaft C and cou ling half A1 is now gradually eliminated by throwing in the main coupling again, so'that at length shaft C revolves at the same speed as coupling half A1, after pipe a3 has been cut olf colnpletely by closing valve E. To reduce tllrottling losses ill the main coupling, vit will be of advantage to reduce at the same time temporarily the rate of revolutions of the Diesel engine by reducing the fuel supply thereto. Shaft B is now driven through A1, c1 C c3, R1,fh1 H, N, n1 by the train H, N at a higher speed than it would be possible by train G, M, so that the free wheel coupling m1 of train G, M automatically is disengaged whereby this traill is put out of the power transmission. Now sleeve R1 is shifted to lefthand end position whereby spur wheel H is coupled with` spur wheel G. This can be done without endangering the gear parts, as spur wheel G which is in connection with half A1 of the main coupling throu h g1, R, f2 F f1, a4, revolves at the sameanguIar speed as sleeve R1 which during the shift is also connected to half A1 through ca C c1, After sleeve R1 has'been shifted, the main coupling is thrown out again. An interruption of the power transmission, however, cannot occur, as spur Wlleel H has been coupled with the driving half of the main coupling independelltly of the coupling action of the latter, through h1, R1, g2 G g1, R, f2 F f1, al4 previous to the commencement of the setting operatioln. Powe ilsnw transmitted o shat B on y throu 1 1 a4, 1 F 2, 1 g2, R1, h1 H, lil, n1. f f g n Willen the gear should be st to the higher speed steps corresponding to wheel trains J, P and K, Q or set again to a lower speed step, thelsetting operations required correspondr to the described ones and need no further detailed explanation.

In the embodiment illustrated in Figure 2, the main coupling is designed as an electromagnetic friction coupling. The driving half, denoted by A5, of this coupling is rigidly connected to .the driving shaft A like IUD 4 half A1 ofthe main'couplin of Figure 1.

'v with the driving half A5 of the main coupling The driven half, denoted by pis rotatably arranged on shaft C between two friction disks a rigidl mounted on coupling half A, and connecte to sleeve F by a spring coupling f corresponding to spring coupllng f1. By another spring coupling T shaft C is in connection with the coupling half A5. As to .the rest, the arrangement corresponds substantially to that illustrated in Figure 1. A dilerence exists only in so far as sleeve R when in its right-hand end position, couples ,the coupling half c2 and, when in medium position, couples sleeve F with spur wheel G, while with sleeve R in left-handend position illustrated in Figure 2, spur wheel G is uncouplcd. As to the mode 'of operation this difference is of no importance. l

As may be seen from th foregoing, the embodiment of Figure 2 differs in=so far from the first-described embodiment as in the former the wheels G, H, J, K are coupled by means of the couplings g1 R c2, h1V R1 0"', i1 R2 0*, and k1 R3 c, while their engagement with the driven half S of the main coupling is establishedby the couplings g1 R f2, 11.1 yR1 g2, z'l R?, h2, and k1 R3 2, that means, the two groups of couplings have exchanged their function. The fundamental characteristic feature of the mode of operation, however, in particular the possibility of passing from one speed step to another without interruption of the power transmission, is not affected by thxsdescribcl modification.

yprovi in t es rin cou lin s 1 Fiure 1, and T,g Fi uiie 2,g thepadvnltsige gis obtained that in t e state of normal operation, when power transmission takes place independently of the couplin action of the main couplin the considerab e variations of the periodica y varying turning moment of the Diesel engine are compensated for in the gear, which variations would cause a rapid wear of the claws of the wheel train couplings, which are operative in the state of normal operation. Furthermore, in the embodiment of Figure'2the provision of the spring coupling f prevents wear of the claws of those wheel train couplings which are used only with thrown-in main coupling.

I claim: 1. In a variable speed gear a driving member, a driven member, a slip clutch, one half of said slip clutch being permanently conl nected to said driving member, at least two gear wheel trains consisting of driving wheels coaxially'with said slip clutch and driven wheels on said driven member, a free wheel coupling for said gear wheel trains, couplings to be operated at will between each of said driving wheels and one half of said slip clutch independently of the other wheels, coupling means to be operated at will between the other half of said slip clutch and the adjacent drivin wheel and coupling means to be operate cent driving wheels.

2. In a device according to claim 1, said couplings including an lintermediate shaft connected to one half of said slip clutch, the driving halves of said couplings being mounted upon said intermediate shaft.

3. In a device according to claim 1, resi]-` ient means interposed between one half of said slip clutch and the driving halves of said couplings, and resilient means interposed between the other half of said slip clutch and the driving members of said coupling means.

The foregoing specification signed at Cologne, Germany, this 8th day of March, 1929.

- HEINRICH HERRMANN.

at will between adja- 

